The following highways were proposed and written into the state Highway Law. However, they were either never built or only partially built. They are still listed in the law to this day, but it is unlikely that they will ever be constructed.

Sunrise Highway exists in Queens from the Belt Parkway to the Queens-Nassau border. Like most state routes in New York City, this segment is locally maintained but carries a state route number, NY 27. If the extension to Amagansett were ever built, the Highway Law calls for the section of Montauk Highway between Flying Point Road (Suffolk CR 39A) and the eastern terminus of Sunrise Highway to be decommissioned.

The Nassau Expressway in Queens was previously designated I-878, but the NYSDOT later downgraded it to a state route. The Nassau Expressway in Nassau has traffic lights at all of its intersections except one, the interchange with Seagirt Boulevard. If there were to be improvements to this road, it is possible that the I-878 designation would be restored to all or part of it.

Interboro Parkway

Direction:

East/West

Western Terminus:

Belt Parkway in Brooklyn

Eastern Terminus:

Grand Central Parkway and Van Wyck Expressway (I-678) in Queens

Status:

Unbuilt from Belt Parkway to Jamaica Avenue. Constructed from Jamaica Avenue to I-678.

Note:

The Interboro Parkway has been renamed the Jackie Robinson Parkway. If the extension to the Belt Parkway were to be built, it would almost certainly carry the new name.

Richmond Parkway

Direction:

North/South

Southern Terminus:

West Shore Expressway (NY 440) on Staten Island

Northern Terminus:

Staten Island Expressway (I-278) on Staten Island

Status:

Constructed from NY 440 to Richmond Avenue. Unbuilt from Richmond Avenue to I-278.

Note:

The Richmond Parkway has been renamed the Korean War Veterans Parkway. If the extension to I-278 were to be built, it would almost certainly carry the new name.

The Shore Front Drive was to begin at the northern terminus of the West Shore Expressway and run along the water all the way around Staten Island to the interchange of the West Shore Expressway with the Richmond Parkway (now the Korean War Veterans Parkway). Since this route is semicircular, it is impossible to say if it would have been considered a north/south route or an east/west route. It is possible that it would have been considered both in different places.